In various industrial production processes a strip-shaped material is wound to form a reel with the aim of achieving an edge alignment as level as possible. In producing metal rolling stock, such as a steel strip or an aluminum strip, the rolling strip emerging from a roll stand is also usually wound to form a coil.
In order to test the quality of a metal strip, a test piece of the metal coil is subjected to an inspection. For this purpose a piece of the rolling strip is unwound from the coil and is wound back on after the test. Here the problem arises that, as the unwound length increases there is a danger that the rolling strip will become misaligned laterally. This results in a telescoped metal coil, at least in the outer windings. Metal strip projecting beyond the front face of the metal coil can then be easily damaged during transportation in subsequent process steps. The overall value of the metal coil can thereby be decreased.
To avoid this problem of lateral misalignment, the length to be unwound might, for example, be limited, or a test piece might be cut off. The former has the disadvantage that the inspection cannot be carried out over the desired length. The latter gives rise to waste material since the severed test piece must be discarded.